1. Faculty of Physics and Computational Materials Physics and Vienna Doctoral School in Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
2. Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Campus Nord, Postfach 3640, D-76021 Karlsruhe, Germany
3. VASP Software GmbH, Sensengasse 8, A-1090 Vienna, Austria
4. Faculty of Physics and Center for Computational Materials Science, University of Vienna, Kolingasse 14-16, A-1090 Vienna, Austria
5. Institut für Physikalische Chemie, Karlsruher Institut für Technologie (KIT), Campus Süd, Postfach 6980, D-76049 Karlsruhe, Germany